Merino Wool:A special, fine grade of wool that originally came from Merino sheep. It shares all of the characteristics classic to wool, but what makes Merino wool different is the luxurious softness and comfort provided by its finer diameter as contrasted to larger diameter fibers. Unlike coarser grades of wool, Merino wool is much less prone to itching.

Stretch Nylon:Continuous nylon filaments that are crimped and heat set to provide elasticity. Due to the relatively high level of elasticity imparted to nylon after it is crimped and heat set, it is very commonly utilized to make stretch socks in combination with other yarns.

Elastic (rubber):A rubber or spandex (synthetic elastic) that provides extreme stretch and recovery. It is usually wrapped with a man-made filament yarn in order to provide consistency in its stretch and recovery.

Acrylic:A man-made fiber that provides softness and warmth with little weight and high durability. Acrylic's inherent properties allow it to hold brighter and more brilliant colors than its natural fiber counterparts.